So it looks like Samsung is offline this morning. This shouldn't bother me - I don't work for them and their network isn't my problem. However it turns out that my Samsung Smart TV thinks there's no internet if there's no www.samsung.com :( - using tcpdump I started looking at what the TV was trying to contact when I pressed the 'Retry' button in the the network settings; this is what the DNS requests/replies to/from the TV look like:

I was hoping it was just using a DNS ping, so I overrode the DNS and pointed it to 127.0.0.1 and tried again. That didn't work so I pointed it at one of my web servers, thinking that it might just be a tcp connect on port 80. That didn't work either - but now I had the HTTP headers, so now I had the file and path too:

I added a vhost for www.samsung.com, mkdir'd the "global/products/tv/infolink" path and touched "us.xml" and clicked retry again - still no dice :( . Concluding it needed a valid XML file I turned to Google, who had thankfully cached a copy - here it is again, in case you need it: